1. Field of the Invention
The present invention relates to an ultrasonic treatment apparatus for performing a medical treatment of a morbid tissue in a living body by using ultrasonic vibrations and RF currents.
2. Description of the Related Art
In an ultrasonic treatment apparatus, a vibration transmission member is generally coupled to the distal end of an ultrasonic vibrator. The distal end of this vibration transmission member is brought into contact with an internal morbid tissue of a patient to transmit ultrasonic vibrations generated by the ultrasonic vibrator to the tissue through the vibration transmission member, thereby performing a treatment, e.g., the excision of the tissue.
When a tissue of a living body is excised by using the above-described ultrasonic treatment apparatus, the tissue often bleeds.
As a means for eliminating such inconvenience, a technique disclosed in U.S. Pat. No. 4,750,488 is known. In this technique, when a tissue bleeds, an RF current is supplied to a vibration transmission member to stop the bleeding.
Problems, however, are posed in terms of electrical safety, if only an RF current for a hemostatic operation is supplied to a vibration transmission member, as in this conventional technique. More specifically, a current may unintentionally flow in an ultrasonic treatment apparatus itself or peripheral devices for introducing the apparatus into a portion in a living body (patient), such as an endoscope, as well as a patient or an operator, thus causing an electric shock or destruction of the apparatus.